Wells are drilled into an earth formation to extend to a target reservoir of interest. The reservoir can include hydrocarbons, fresh water, or other fluids of interest for production to the earth surface. Alternatively, fluids can be injected from the earth surface into the reservoir within the formation.
Many wells include horizontal segments that run relatively horizontally through a reservoir. However, a “horizontal” well segment is usually not perfectly horizontal, since there usually are local deviations from the horizontal direction in the “horizontal” well segment. Such local deviations include slanted portions that can be slanted upwardly or downwardly such that the slanted portions are angled with respect to the horizontal direction.
Measuring such local deviations from the horizontal direction in a “horizontal” well segment can be challenging using conventional techniques. One example of a conventional technique of surveying a well includes running an intervention tool into the well, such as on a wireline or other carrier structure. The intervention tool includes various types of sensors, including navigation sensors (e.g., inertial sensors such as gyroscopes and accelerometers), or sensors referencing the earth's magnetic field or gravitational field. However, having to run an intervention tool for measuring local deviations of the well from the horizontal direction can be time consuming and costly.